IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2025-07-02 DOI: 10.1016/j.camwa.2025.06.021

Zongcheng Li , Jin Li

引用次数: 0

Estimating the risk of cancer with and without a screening history. 评估有和没有筛查史的癌症风险。

IF 1.2 3区数学

Lifetime Data Analysis Pub Date : 2025-07-02 DOI: 10.1007/s10985-025-09662-1

Dongfeng Wu

引用次数: 0

Robust functional inverse regression 稳健函数逆回归

IF 1.4 3区数学

Journal of Multivariate Analysis Pub Date : 2025-07-02 DOI: 10.1016/j.jmva.2025.105472

Haoyang Cheng , Jianjun Xu , Qian Huang

{"title":"Robust functional inverse regression","authors":"Haoyang Cheng , Jianjun Xu , Qian Huang","doi":"10.1016/j.jmva.2025.105472","DOIUrl":"10.1016/j.jmva.2025.105472","url":null,"abstract":"<div><div>Functional sufficient dimension reduction (FSDR) is a popular approach for supervised dimensionality reduction in regression settings, as it allows for the reduction of functional predictors to a lower-dimensional subspace without loss of information. However, most existing FSDR methods are vulnerable to heavy-tailedness or outliers, which are common in many real-world applications. To address this limitation, we propose a robust FSDR method that utilizes a functional pairwise spatial sign (PASS) operator. This approach is suitable for both completely observed functional data and sparsely observed longitudinal data. Our method provides a more robust approach to FSDR, by taking into account the spatial information of the data and assigning greater weights to the less outlier-prone observations. We also provide a convergence rate analysis of the estimator, demonstrating that our method yields a consistent estimate of the dimension reduction directions. The effectiveness of our proposed method is demonstrated through extensive simulations and real data analysis. Our method outperforms existing methods in terms of robustness and accuracy, making it a valuable tool for analyzing functional data across various applications.</div></div>","PeriodicalId":16431,"journal":{"name":"Journal of Multivariate Analysis","volume":"210 ","pages":"Article 105472"},"PeriodicalIF":1.4,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144562999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Combinatorics on bi-γ-positivity of 1/k-Eulerian polynomials 1/k-欧拉多项式双γ正性的组合

IF 0.9 2区数学

Journal of Combinatorial Theory Series A Pub Date : 2025-07-02 DOI: 10.1016/j.jcta.2025.106092

Sherry H.F. Yan , Xubo Yang , Zhicong Lin

{"title":"Combinatorics on bi-γ-positivity of 1/k-Eulerian polynomials","authors":"Sherry H.F. Yan , Xubo Yang , Zhicong Lin","doi":"10.1016/j.jcta.2025.106092","DOIUrl":"10.1016/j.jcta.2025.106092","url":null,"abstract":"<div><div>The <span><math><mn>1</mn><mo>/</mo><mi>k</mi></math></span>-Eulerian polynomials <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>n</mi></mrow><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi>x</mi><mo>)</mo></math></span> were introduced as ascent polynomials over <em>k</em>-inversion sequences by Savage and Viswanathan. The bi-<em>γ</em>-positivity of the <span><math><mn>1</mn><mo>/</mo><mi>k</mi></math></span>-Eulerian polynomials <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>n</mi></mrow><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi>x</mi><mo>)</mo></math></span> was known but to give a combinatorial interpretation of the corresponding bi-<em>γ</em>-coefficients still remains open. The study of the theme of bi-<em>γ</em>-positivity from a purely combinatorial aspect was proposed by Athanasiadis. In this paper, we provide a combinatorial interpretation for the bi-<em>γ</em>-coefficients of <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>n</mi></mrow><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi>x</mi><mo>)</mo></math></span> by using the model of certain ordered labeled forests. Our combinatorial approach consists of three main steps:<ul><li><span>•</span><span><div>construct a bijection between <em>k</em>-Stirling permutations and certain forests that are named increasing pruned even <em>k</em>-ary forests;</div></span></li><li><span>•</span><span><div>introduce a generalized Foata–Strehl action on increasing pruned even <em>k</em>-ary trees which implies the longest ascent-plateau polynomials over <em>k</em>-Stirling permutations with initial letter 1 are <em>γ</em>-positive, a result that may have independent interest;</div></span></li><li><span>•</span><span><div>develop two crucial transformations on increasing pruned even <em>k</em>-ary forests to conclude our combinatorial interpretation.</div></span></li></ul></div></div>","PeriodicalId":50230,"journal":{"name":"Journal of Combinatorial Theory Series A","volume":"217 ","pages":"Article 106092"},"PeriodicalIF":0.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simultaneous direct sum decompositions of several multivariate polynomials 几个多元多项式的同时直接和分解

IF 1 3区数学

Linear Algebra and its Applications Pub Date : 2025-07-02 DOI: 10.1016/j.laa.2025.06.022

Lishan Fang, Hua-Lin Huang, Lili Liao

引用次数: 0

Pressure correction method with time filter for incompressible Navier–Stokes equations 不可压缩Navier-Stokes方程的时间滤波压力校正方法

IF 3.4 2区数学

Communications in Nonlinear Science and Numerical Simulation Pub Date : 2025-07-02 DOI: 10.1016/j.cnsns.2025.109102

Ning Li , Jilian Wu , Xinlong Feng , Yi Li

{"title":"Pressure correction method with time filter for incompressible Navier–Stokes equations","authors":"Ning Li , Jilian Wu , Xinlong Feng , Yi Li","doi":"10.1016/j.cnsns.2025.109102","DOIUrl":"10.1016/j.cnsns.2025.109102","url":null,"abstract":"<div><div>In this paper, we present standard pressure correction (SPC) and rotational pressure correction (RPC) methods with time filters for two- or three-dimensional (2D/3D) time-dependent incompressible Navier–Stokes equations. The core technique of these methods is to add a time filter at each time step after the original first- and second-order pressure correction methods, which not only decouples velocity and pressure, but also improves the temporal accuracy from first-order to second-order and from second-order to third-order, while not increasing additional computational complexity. Furthermore, combining the original pressure correction method, the pressure correction method plus time filter and the adaptive algorithm design idea, we constructed easy-to-implement adaptive time stepsize pressure correction algorithms and variable stepsize, variable order (VSVO) pressure correction algorithms. We also prove that both first-order SPC and RPC algorithms plus time filter are unconditionally stable and establish error estimates of the velocity for the first-order SPC method plus time filter. Finally, we provide numerical tests to demonstrate the performance of the proposed algorithm, with particular emphasis on the outstanding results achieved by the VSVO pressure correction method.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"151 ","pages":"Article 109102"},"PeriodicalIF":3.4,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fully distributed pinning synchronization of coupled Takagi-Sugeno fuzzy neural networks with aperiodic intermittent communication 具有非周期间歇通信的耦合Takagi-Sugeno模糊神经网络的全分布钉钉同步

IF 3.2 1区数学

Fuzzy Sets and Systems Pub Date : 2025-07-02 DOI: 10.1016/j.fss.2025.109519

Dan Liu , Kaibo Shi , Xiaohong Cui , Kun Zhou , Binrui Wang

引用次数: 0

On special H -matrices based on Beauwens condition 基于Beauwens条件的特殊H矩阵

IF 1.1 4区数学

Linear & Multilinear Algebra Pub Date : 2025-07-02 DOI: 10.1080/03081087.2025.2523277

Srđan Milićević, Maja Nedović

引用次数: 0

Bipartite friends and strangers walking on bipartite graphs 在二部图上行走的二部朋友和陌生人